This invention relates to an automatic eyeglass lens grinding method and machine in which a desired shape, for example the shape of the interior of the lens frame of eyeglasses, is recorded on a substrate which is thereafter scanned. During this scanning process, electrical signals are generated which indicate the presence or absence of the recorded pattern. By controlling the movement of the lens toward and away from the grinding wheel relative to the generated signals, the lens is automatically shaped so as to correspond with the recorded pattern.
When eyeglasses, particularly for correction of vision, are formed in the conventional manner, lenses and frames of various shapes are separately stored. After correct lenses have been prescribed, a frame is selected from a wide variety of differently shaped frames and the lenses must be shaped to match with the selected frame and fixed therein.
Recently in forming the lenses by grinding, a simple grinder is used, wherein a replica pattern plate having a same shape as the eyeglass frame is used. The pattern plate is located co-axially with the axis of the objective lens to be ground, and the lens is pressed against a highspeed rotating grinder until the pattern plate communicates against a stop device which has the same radius as the outer periphery of the grinder stone. As the lens and pattern plate are turned, the lens acquires the same shape as the pattern plate. In such machine, however, many pattern plates corresponding to the various frames are required. Such a requirement is burdensome because so many frames of many various designs are available. For such purposes a machine for forming the various patterns has been developed, but the machine does not always produce the hoped for results. Applicants have found the machine has broken frames and suffers mechanical problems as well.